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United States Department of Agriculture

Agricultural Research Service

Title: Response of Codling Moth and Navel Orangeworm Life Stages to Vacuum

Authors
item JOHNSON, JUDY
item Valero, Karen

Submitted to: Methyl Bromide Alternatives and Emissions Research Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: August 20, 2002
Publication Date: November 20, 2002
Citation: JOHNSON, J.A., VALERO, K.A. RESPONSE OF CODLING MOTH AND NAVEL ORANGEWORM LIFE STAGES TO VACUUM. METHYL BROMIDE ALTERNATIVES AND EMISSIONS RESEARCH CONFERENCE PROCEEDINGS. 2002.

Interpretive Summary: California tree nuts and fresh fruits often require quarantine or phytosanitary treatments to disinfest product of field pests such as codling moth, Cydia pomonella, and navel orangeworm, Amyelois transitella. The impending loss of the current treatment of choice, the rapid-acting fumigant methyl bromide, requires that alternatives be developed. Vacuum treatments that apply reduced pressures of more than 27 in Hg in flexible containers have been used to treat a variety of durable products. The mode of action for these treatments appears to be similar to low oxygen treatments, although the treatments times are often substantially lower for vacuum treatments. As part of a project to test the efficacy of vacuum treatments to disinfest dried fruits and nuts, the relative tolerance of different life stages of codling moth and navel orangeworm was determined in the laboratory. At both 25 and 35C, the stage of codling moth most tolerant to vacuum was the diapausing larva. After 72 hours at 25C, mortality of diapausing codling moth larvae was only 4.7%, while all other stages were 99% or above. Mortality occurred much faster at 35C, with 69% of diapausing codling moth larvae killed after 16 hours. At 25C, the stage of navel orangeworm most tolerant to vacuum was the fifth instar larva. After 48 hours of exposure, mortality of fifth instar larvae was only 30%, in contrast to 100% for pupae and 87% for eggs. Diapausing codling moth larvae were more tolerant than the most tolerant stage of the navel orangeworm.

Technical Abstract: California tree nuts and fresh fruits often require quarantine or phytosanitary treatments to disinfest product of field pests such as codling moth, Cydia pomonella, and navel orangeworm, Amyelois transitella. The impending loss of the current treatment of choice, the rapid-acting fumigant methyl bromide, requires that alternatives be developed. Vacuum treatments that apply reduced pressures of more than 27 in Hg in flexible containers have been used to treat a variety of durable products. The mode of action for these treatments appears to be similar to low oxygen treatments, although the treatments times are often substantially lower for vacuum treatments. As part of a project to test the efficacy of vacuum treatments to disinfest dried fruits and nuts, the relative tolerance of different life stages of codling moth and navel orangeworm was determined in the laboratory. At both 25 and 35C, the stage of codling moth most tolerant to vacuum was the diapausing larva. After 72 hours at 25C, mortality of diapausing codling moth larvae was only 4.7%, while all other stages were 99% or above. Mortality occurred much faster at 35C, with 69% of diapausing codling moth larvae killed after 16 hours. At 25C, the stage of navel orangeworm most tolerant to vacuum was the fifth instar larva. After 48 hours of exposure, mortality of fifth instar larvae was only 30%, in contrast to 100% for pupae and 87% for eggs. Diapausing codling moth larvae were more tolerant than the most tolerant stage of the navel orangeworm.

Last Modified: 9/10/2014
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